Well I must admit that I've been guilty somewhat of this behavior. In 2008 when I got my first HD video camera, my tripod was set up dead in the middle of the main line on top of Tehachapi Loop directly above tunnel #9. I was filming a train climbing. As it looped around and got closer, I realized to myself "Hey dummy! You had a brain fart and set up the camera on the track the train is on... move it".

So I calmly moved the camera to the siding track and continued to film. A climbing train is so slow that you have plenty of time to get out of the way. They are pretty slow going down the grade too.
Passenger trains (especially light commuter trains) are especially dangerous. They are fast and very quiet in comparison to a heavy freight train. When I lived in Milwaukee for a bit, a Milwaukee-Chicago Amtrak Hiawatha commuter train going 70mph snuck up on me while I was walking a few feet along the side of the tracks on a curve. I heard the rails and the wind resistance sound first, turned my head and there it was. Took me by complete stealthy surprise. Scared me for a second. He gave a quick toot of the horn and it whooshed past me. A few feet closer and I'd be slammed. Luckily I keep that distance in mind when I walk besides tracks to avoid being hit.
